The recent fatal condo-building collapse has driven three members of victims' families into depression, with three others having suicidal moods.
Mental Health Department director-general Dr Jessada Chokdamrongsuk said yesterday.
He added that the hardest-hit were those who lost five family members in this single accident.
On August 11, a six-storey building that was under construction at the U Place condominium project in Pathum Thani crumbled down, trapping several workers. The collapse claimed 14 lives and injured many more.
Jessada said lesser-affected victims had developed adjustment disorders with depression and acute stress disorder. Symptoms include poor concentration, startled response, anxiety and insomnia.
"If their symptoms don't stop within four weeks, they are at risk of suffering post-traumatic stress disorder," he said.
The Mental Health Department has already extended rehabilitation help to seven families who lost members in the accident. Mental health checks have also been offered to survivors and witnesses.
The department's deputy director-general, Dr Panpimol Wipulakorn, said her agency was also tracking Cambodian survivors.
"They too should undergo mental health checks," she said.
Meanwhile, investigators said they had received information from 40 relevant people. "Of the seven suspects, five have surrendered and are now out on bail," Pathum Thani police chief Maj-General Smith Mukdasanit said.
These suspects are charged with recklessness causing the deaths of others. He added that two other suspects included constructor Chanaichon Kerdthes, a son of a former top-ranking policeman Chalor.
According to Smith, Chanaichon has not yet contacted police. His surrender could have speeded up the investigation.
The Engineering Institute of Thailand has inspected the site of the accident to determine what exactly caused the accident and who should be held responsible.